Sliding contact packings of various kinds are known and have been known for many years. One such sliding contact packing is a cup seal 1 shown in FIG. 1. The cup seal includes an innermost lip 2, the inner diameter of the opening defined by the lip being variable due to the compressibility of the resilient material of the lip 2. The lip 2, as well as the entirety of the resilient seal member, can be made of leather or rubber composition with the radially outermost segment thereof being compressed between a pair of forced fit, telescoping cup-shaped metal casing members 3 and 4.
In order to install the seal 1 onto a shaft, great care has to be taken to prevent the lip 2 from tucking under or somehow becoming positioned on the shaft so that a portion of the seal 2 will permit the escape of fluid therepast. FIGS. 1 to 3 illustrate one type of device that has heretofore been used for purposes of installing the seal 1 onto a rotary shaft. The prior art device includes a guide member 6 having an end portion 7 that is smaller in diameter than the diameter of the hole formed by the lip portion 2 of the seal. The end 8 of the guide member 6 remote from the small diameter end 7 is of a size equal to the shaft diameter over which the seal 1 is to be placed. A conical segment 9 interconnects the end 8 with the small end 7.
In use, the seal 1 is placed so that the opening defined by the lip 2 receives therethrough the small end 7 of the guide member 6. The seal 1 is carefully slid along the length of the guide member first causing the lip 2 to slide onto the conical segment 9 and then causing the lip 2 to slide along the length of the cylindrical end segment 8 until the endmost portion 10 of the lip 2 is spaced a sufficient distance from the end wall 11 of the guide member 6. Extreme care must be exercised by the user to make sure that the lip 2 does not become tucked under or otherwise deformed during the aforesaid process so as to prevent the formation of a proper seal.
As is illustrated in FIG. 2, the guide member 6 has a hollow interior to enable the receipt therein of a shaft 12 around which the seal 1 is to be installed. The cylindrical end segment 8 of the guide member 6 is generally equal in its outer diameter to the outer diameter of the shaft 12. Thus, once the seal is oriented in its proper location on the guide member 6, the seal and the guide member 6 are both placed over the end of the shaft 12 until the end wall 11 of the guide member 6 abuts against a shoulder 13 on the shaft 12. It is common practice to provide a shoulder 13 an incremental distance from the bottom 14 of a counterbore 15 in an opening 16 through which the shaft 12 extends. The seal 1 is to, following assembly, occupy the space between the shoulder 13 and the bottom 14 of the counterbore.
Following a placement of the guide member 6 and associated seal 1 over the end of the shaft 12, a handle part 17 having an opening 18 therein is positioned so that the guide member 6 is received into the opening 18 in the position illustrated in FIG. 2. The user thereafter applies an axial force to the handle part 17 urging the seal member 1 into an encircling relation to the shaft 12 as illustrated in FIG. 3 and forced fit into the counterbore 15. It is preferred that the cylindrical wall 8 of the guide member 6 be approximately equal to or slightly less than the inner diameter of the opening 18 in the handle part 17 so that an appropriate guiding relation exists between the guide member 6 and the handle part 17.
The aforedescribed apparatus has fulfilled a basic need for facilitating the installation of cup seals onto shafts to form a shaft packing. However, in an effort to minimize the amount of time that it takes to install the cup seal, users of the apparatus oftentimes do not exercise the required amount of care to prevent the lip 2 of the seal 1 from tucking under or otherwise deforming to thereby prevent the formation of a positive seal between the lip 2 and the peripheral surface of the shaft 12. Accordingly, it is desirable to provide a device which will enable the quick installation of a cup seal onto a shaft.
Accordingly, it is an object of this invention to provide a seal installation device facilitating the quick installation of a cup seal onto a shaft to form a sliding contact packing.
It is a further object of the invention to provide a seal installation device, as aforesaid, which is simple and inexpensive in its construction, is made of durable components to thereby enable its use in the field without attention to maintenance and the like.
It is a further object of the invention to provide a seal installation device, as aforesaid, wherein a minimum of instruction will be required to enable the user thereof to quickly assemble a cup seal into an encircling and sealing relation to the rotary shaft.